In the sector of industrial manufacture, the demand exists for simple pretreatment techniques in order to improve the adhesive bonding properties of the adherend.                Costly and inconvenient processes such as wet-chemical cleaning and priming of the adherend surface are typically used in order to obtain high-strength bonds with a self-adhesive tape.        More particularly the simple physical pretreatment techniques under atmospheric pressure (corona, plasma, flame) are nowadays used with advantage for the surface treatment of the adherend, for the purpose of achieving a higher anchoring force with a self-adhesive tape.        
Where two or more than two layers are to be laminated to one another, one or both interfaces are typically pretreated physically prior to the lamination.
It is known that treatment by corona and plasma has limited durability in respect of the activation of the boundary layer, and so treatment takes place at a time near to or predominantly directly before the laminating operation.
Plasma and corona pretreatments are described or referred to for example in DE 2005 027 391 A1 and DE 103 47 025 A1.
In DE 10 2007 063 021 A1 it is claimed that the prior plasma/corona pretreatment is beneficial for the holding power and the flow-on behavior of the adhesive bond. There was no recognition that the process may produce an increase in the bond strength.
DE 10 2006 057 800 A1 claims a multi-ply adhesive tape comprising at least with two pressure-sensitive adhesives A and B which lie directly on one another and which are each pretreated chemically and/or physically prior to lamination. The improved integral adhesion of the layers of pressure-sensitive adhesive that is achieved by this means is obtained by both-sided equal-sided nature of the pretreatment.
In relation to corona treatments under process gas atmosphere, DE 44 38 533 A1 describes a process for corona treatment that includes process gas such as, for example, carbon dioxide or carbon monoxide and also other gases, which are referred to therein as inert gases, such as nitrogen or argon, for example.
Further known prior art is published via DE 10 2007 011 235 A1 to Plasmatreat GmbH, Steinhagen, which describes an improved pretreatment, more particularly cleaning of a surface of a workpiece. For example, adhesive bonding to another workpiece may be considerably improved.
In EP 0 740 681 B1, moreover, the treatment is disclosed at the surface of a polymer or polymer matrix composite material by means of plasma/corona and a coupling agent, and the application of an adhesive or a self-adhesive tape.
Plasma treatment, in particular with a suitable process gas, of heat-activatable tackifying resin layers and hotmelt layers are also known for a high strength of bonding to a pressure-sensitive adhesive layer.
Examples of the latter are found in EP 1 262 532 B1, which is directed to a dual-functional adhesive tape, comprising a heat-activatable tackifying resin layer based on polyolefin and a pressure-sensitive adhesive layer based on acrylate, the polyolefin layer being N2 corona treated, in order in this way to achieve effective anchoring to the pressure-sensitive adhesive layer.
A feature of the prior art is that the pretreatments relate predominantly to the carrier material or to the adherend, in order to build up a higher anchoring force to the adhesive or self-adhesive tape.
It is an object of the invention to find further positive effects in the case of physical surface modification of pressure-sensitive adhesives and carrier materials, in order to achieve high-strength bonds. The nub of the object is the achievement of a high anchoring between the pressure-sensitively adhesive layer and carrier material; as a secondary aspect, the aim is also to fulfill the object when a relatively long time period lies between the physical treatment and lamination.